1. Field of the Invention
The present invention relates generally to noise suppression in a GSM mobile terminal and, more particularly, to a Global System for Mobile communication (GSM) mobile terminal and noise suppression method for the same for suppressing Time Division Multiple Access (TDMA) noise in an audio signal during call processing.
2. Description of the Related Art
GSM is currently the most popular standard for digital mobile terminals. Several GSM users are capable of sharing the same channel to send compressed digital data, and the channel is divided into time slots, each of which is assigned to a user. GSM mobile terminals operate at frequency bands of 900 MHz and 1800 MHz.
GSM has over 120,000,000 users, and is utilized in 120 countries. Many GSM network operators have made international roaming agreements, allowing users to carry their own mobile terminals while traveling in foreign countries.
A GSM mobile terminal employs a TDMA channel access scheme, in which a transmit interval for data transmission and a receive interval for data reception alternate with each other. There is a significant difference between the amount of power consumption in the transmit interval and that in the receive interval. Power consumption in the transmit interval is much higher than that in the receive interval, which gives rise to TDMA noise of a particular frequency. A capacitor connected to the power terminal can be effective for TDMA noise suppression. However, the capacitor may not be sufficient in suppressing the noise, and development of a more effective technique for TDMA noise suppression is necessary.